1. Field of the Invention
The present invention relates to a process for economically producing L-ascorbic acid-2-sulfate and salts thereof of high purity in high yield. These compounds are useful as medicines, domestic medicines, animal medicines and as additives for food, feed and cosmetic materials.
2. Description of the Prior Art
The synthesis of salts of L-ascorbic acid-sulfate has been demonstrated by reaction of pyridine-sulfur trioxide complex with 5,6-O-benzylidene-L-ascorbic acid and then converting the product to the potassium salt thereof. [T. M. Chu et al. Steroids 1968, 12, (3) 309-321; S. F. Quadri, Diss Abstr. Int.B, Vol 34 (9) 4431 - 4432 (1974); S. F. Quadri, et. al., Carbonhyd. Res. Vol. 29 (1) 259 - 264 (1973); Murata Japanese Unexamined Patent Publication No. 30354/1974 (1974)]. However, the yield from such process has been low, and high purity products could not be obtained. Accordingly, a need exists to provide a method by which L-ascorbic acid-L-sulfate and salts thereof, can be produced economically in high yields and high purity.